Inspection systems for the analysis of moving web materials have proven critical to modern manufacturing operations. Industries as varying as metal fabrication, paper, non-wovens, and films rely on these inspection systems for both product certification and online process monitoring. Equivalent verification of product quality is much more expensive if performed off-line or manually after fabrication of the web materials.
A difficult factor in the design of all such inspection systems is the high rate of data acquisition and processing. Conventional commercial web manufacturing operations utilize web dimensions and web speeds requiring inspection data acquisition rates of tens or even hundreds of mega-pixels per second. Furthermore, these data rates are provided in a continuous manner in order to fully scan the moving web. The noted data rates are considered extensive and have resulted in the development of custom image processing engines to address the large continuous data rates.
The art has responded to this dilemma by using dedicated electronic hardware to preprocess the data stream, generally utilizing multiple paths and multiple layers of dedicated modules. Such a system is capable of sustaining the data rates required for the inspection of moving webs. However, there are difficulties related to the necessary customization of both hardware and software required for the dedicated preprocessors. These inspection systems are highly custom, thus limiting the range of applications possible with a given system. For example, a system developed for inspecting metals will not be able to also inspect printed packaging. Because of this customization, dedicated electronic hardware also require high development costs in both money and time, they are relegated to performing only simple image processing operations in real time, and they have limited future expansion and correspondingly high maintenance costs.
The manufacturing industry has recognized the importance of flexibility in its operations. Achieving this goal often has manufacturers working to develop systems and devices that allow a rapid change over between various products. Unfortunately, while web inspection systems have proven valuable and even indispensable for some industries, they have not been successful in addressing the increased pace of change in manufacturing. Specialized signal processing hardware does not permit the rapid change over between various products that optical inspection of moving webs now requires. It would be desirable to be able to perform all the required processing on a single general-purpose computer, so that change over between product lines could be accomplished by merely loading the required software. Additionally, it would also be desirable to reduce the development time and cost associated with custom hardware systems. So far, that end has not been possible.